This invention relates to exercising apparatus for a user to simulate the motions, exertions and techniques involved in skiing, thereby increasing the user""s strength and skill, and more particularly to improvements in such apparatus.
Apparatus for use by skiers on which they may simulate the motions, exertions and techniques required in skiing has been built and sold for several years. In particular U.S. Pat. No. 3,524,641 was issued to Robert J. Ossenkop on Aug. 18, 1970, for a device comprising a movable carriage on a set of rails. The carriage of that device is constrained in its movement on the rails by flexible members attached to both the carriage and to transverse members between the rails near each end of the set of rails, and a user can move the carriage from side to side on the rails to simulate the Wedeln or xe2x80x9cparallelxe2x80x9d technique of skiing.
U.S. Pat. No. 3,547,434 was issued to the same inventor on Dec. 15, 1970. This later patent is for a device similar to the first device, but comprising a number of improvements, such as movable footrests on the carriage whereby a user may simulate turning and edging techniques in addition to parallel skiing; and, in some embodiments may also move the feet relative to one another.
The inventions referenced above each include a safety strap attached to a transverse member between the parallel rails and to the carriage on the rails in addition to the flexible member by which the carriage is constrained to travel on the rails. The purpose of the safety strap is to provide for a situation in which the aforementioned flexible member might rupture on one side of the carriage, providing a sudden force urging the carriage to the side where the flexible member remains unruptured, which sudden force could dislodge a user and perhaps cause serious injury. The safety strap in such instance provides a restoring force toward the center tending to lessen the amplitude of carriage displacement that might otherwise occur.
In U.S. Pat. No. 4,743,014, to which this case is related, and by the same inventor, an exerciser is disclosed having a pair of spaced-apart rails, a platform for riding on the rails, a first resilient element providing a first restoring force on the platform, and a second resilient element providing a second restoring force on the platform. The second resilient element has an adjustment element contacting the second resilient element in at least three points.
In the latter exerciser, the rails are held in a spaced-apart relationship by a brace element in the center, which is fastened to the rails by screw-type fasteners, and by transverse elements fastened at the ends of the rails. The transverse elements at the ends are tubular in form, and the rails pass through openings in the tubular transverse elements, fastening to a bracket internal to each tubular transverse element. This joining arrangement is illustrated by FIGS. 1A and 1B of the referenced patent. As shown in these figures rails 301 and 303 pass through holes 305 and 307 respectively into tubular transverse element 309. Inside, the rails are fastened to a bracket 311 by screw fasteners 313 and 315. Rubber-like end caps 317 and 319 close the ends of the tubular transverse element after assembly and act as non-skid pads in contact with the floor in operation. The end caps are of molded rubber-like material, and disk-like pieces carrying designs and lettering are added for identification and aesthetic effect. This particular method of joining and spacing the rails has not proved entirely satisfactory in terms of cost and ease of assembly, and in terms of strength and rigidity of assembly, and the multiple-piece construction of the end caps has also proved to be relatively expensive.
Although related U.S. patents issued to the inventor address the above problem and other problems related to construction and function of various components of the parent ski exerciser, there are. still non-obvious improvements desired in several areas related to construction or assembly techniques, profile, materials, and longevity of the apparatus. For example, in U.S. Pat. No. 5,147,257 (hereinafter ""257), in FIGS. 5A and 5B, a ski exerciser is illustrated both in an elevation view (FIG. 5A), and in a plan view (overhead FIG. 5B). Arcuate rails 15 comprise tubing structures having a continuous arc or bow over their entire length.
It has been discovered through empirical method that an even better action may be simulated with rails shaped somewhat differently than in the prior art. Firstly, the tubing material used in rails 15 can be changed to exhibit even more strength than previously. Secondly, the inventor has discovered that other shapes for the rails than fully arcuate provide better skiing feel than the fully arcuate rails in the referenced prior patents.
FIG. 5A in ""257 illustrates roller assemblies housing rollers such as rollers 25 and 27 which are identical in size and construction with other illustrated rollers which make rolling contact with resilient members 23 and 59. The diameter of the aforementioned rollers is disclosed as approximately 1 inch, and the rollers are generally cylindrical. It has been discovered that larger rollers, also crowned have a beneficial effect in smoother power band operation. The crowned rollers keep the belts better centered on the rollers.
The present inventor has also determined that improvements may be made in the positioning of wheels for the wheeled carriage, and in the form of the rails and how the wheels interface to the rails.
What is clearly needed is a modularly enhanced ski-excising device that provides further distinct advantages for the expanding field of users. Such a device could be manufactured with fewer assembly parts, retain a lightweight characteristic, provide additional stability and rigidity, and require less work for a user to assemble and operate, as well as providing for a more realistic workout.
In a preferred embodiment of the present invention a ski exercising machine is provided, comprising a set of at least two parallel rails joined to cross members at the ends, the cross members providing support on a horizontal support surface, and joined to a central frame structure extending from the horizontal surface near the center to the rails, the rails extending from each cross member at each end upward at an acute angle with the horizontal rising to a maximum height in the center; a wheeled carriage riding on the rails; at least one articulated footpad mounted to the wheeled carriage; and a first power band having two ends, anchored at both ends by a clamp to a bottom surface of the frame structure beneath the wheeled carriage, passing over first rollers fixed to the cross members, and anchored to the wheeled carriage, such that the power band is extended and exerts a restraining force toward the center of the machine as the wheeled carriage translates on the rails to either side of center. The set of rails is characterized in that the rails have a central arcuate portion and straight portions extending from each cross member to the central arcuate portion.
In some embodiments the cross members are spaced apart more than 48 inches, and the arcuate portion extends for at least one third of the overall length. Also in some embodiments there are two articulated footpads mounted to the wheeled carriage, each footpad having a contact surface for a user""s foot and pivoted to rotate about an axis orthogonal to the direction of the rails, the axis below the level of the contact surface. In some embodiments footpads mount to an upper tray assembly adapted to removably fasten to the wheeled carriage, forming thereby a quick-change module.
In a preferred embodiment the first power band is clamped to an undersurface of the wheeled carriage at two positions, one each at each end of the wheeled carriage, such that the first power band lies flat along the width of the wheeled carriage under the wheeled carriage. Also in a preferred embodiment the cross members at the ends are welded to the rails and the rails are welded to the central frame structure, and the bottom surface of the central frame structure is joined by welding to the cross members on each end by power band guides, the power band guides, the cross members, and the bottom surface of the central frame structure all lying parallel to and adjacent the horizontal surface. The first rollers fixed to the cross members are positioned such that the first power band anchored at the ends to the clamp at the bottom surface of the frame structure lies in the power band guides to each side of the central structure, passing under and over the rollers to the wheeled carriage, the power band guides acting as protective members preventing the first power band from contacting the horizontal support surface.
In most embodiments there is a second power band within the first power band, the second power band having ends both fastened at the clamp holding the ends of the first power band above the ends of the first power band, the second power band extending to second rollers rotatably mounted to a structure welded to the bottom surface of the central frame structure to each side of center, the second power band passing under and over the second rollers back toward center, and over a third roller rotatably mounted under the wheeled carriage. The third roller is mounted spaced apart from the first power band clamped to the undersurface of the wheeled carriage by about twice the thickness of the power band, such that the second power band passing over the roller contacts both the roller and the first power band.
In some embodiments the wheeled carriage has weight-bearing wheels positioned to ride on upper surfaces of the rails and keeper wheels opposite individual ones of the weight-bearing wheels, the keeper wheels contacting undersurfaces of the rails, such that the wheeled carriage so equipped is positively retained on the rails. Also in some embodiments two articulated footpad assemblies each comprises a foot contact area having front and back upward extensions pivotally joined to frame elements above the footpad area, forming swing-cradle footpads. In a special embodiment the two swing-cradle footpad assemblies each mount slidably by an interface to the upper tray, the interface including a lock-unlock mechanism whereby the footpad assemblies may be unlocked, adjusted in position on the upper tray, and relocked, so the center distance between the footpads may be readily adjusted.
The two articulated footpads may be joined by at least one link, such that the footpads are constrained to rotate together about their respective axes, and the footpads have a home position wherein the footpads are each canted inward, the degree of cant determined by the length of the link. In some cases the link is adjustable, such that the degree of cant at the home position may be adjusted.
In yet another embodiment there is a snowboard footpad simulating a snowboard mounted on an interchangeable upper tray assembly, the snowboard footpad being rotatable about an axis orthogonal to the direction of the rails, and having a length in the direction of the axis significantly more than the width of the wheeled carriage riding on the rails, and extending beyond the wheeled carriage on both sides. The snowboard footpad has a surface for a user""s feet, and the axis for pivoting is above the level of the surface for the user""s feet.
In several embodiments the rails are extruded each having a groove in an upward facing surface, and the wheeled carriage includes wheels that ride within the groove in the upward-facing surface. In some other embodiments there is also a groove in a downward-facing surface of each rail, and the wheeled carriage includes wheels engaging both the upward-facing and downward-facing grooves. In yet other embodiments each rail has a xe2x80x9cCxe2x80x9d cross-section comprising internally an upper, downward-facing track and a lower, upward-facing track, and wherein the wheeled carriage has two or more wheels guiding on the upper track and two or more wheels guiding on the lower track.
In yet another embodiment of the invention a ski exercising machine is provided, comprising a set of at least two parallel rails joined to cross members at the ends, the cross members providing support on a horizontal support surface, and joined to a central frame structure extending from the horizontal surface near the center to the rails, the rails extending from each cross member at each end upward at an acute angle with the horizontal rising to a maximum height in the center; a wheeled carriage riding on the rails; at least one articulated footpad mounted to the wheeled carriage; and a set of three power bands each anchored at both ends by a clamp to a bottom surface of the frame structure beneath the wheeled carriage, passing over separate roller sets, with one or more of the power bands anchored to the wheeled carriage and one or more passing over a roller anchored to the wheeled carriage.
In the many embodiments of the present invention significant improvements are provided over ski-exercise machines known in the art, the improvements making such equipment more durable, less expensive to build, and providing even more realistic operation.